Method and means for registering printing plates



W. F. HUCK HETHOD AND MEANS FOR REGISTERING PRINTING PLATES Filed June 23, 1936 9 Sheets-Sheet 1 INV ENTOR- 031, 1939. w. F. HUQK} 2,117,653

IE'IHOD AND HEARS FOR REGISTERING PRINTING PLATES Filed June 25, 1936 9 Sheets-Sheet 2 I. I .ai 5 a, 5 55/ 53 I vzu'roia. .B 5/ 465% Oct. 31', 1939. w. F. HUCKQ IETHOD AND MEANS FOR REGISTERING PRINTING PLATES 9 Sheets-Sheet 3 Filed June 23, 1936 INVENTOR I A'rf 0a. 31, 1939. v HUK v 2,177,653

IETHOD ANDJIEANS FOR REGISTERING- PRINTING PLATES I Filed June 23, 1936 9 Sheets-Sheet 4 Oct. 31, 1939. w, F, HUCK 2,177,653

METHOD AND MEANS FOR REGISTERING PRINTING PLATES Filed June 23, 1936 9 Sheets-Sheet 5 Oct. 31, 1939. w. F. HUCK METHOD AND MEANS FOR REGISTERING PRINTING PLATES Filed June 25; 1936 9 Sheets-Sheet s W. F. HUCK METHOD AND MEANS FOR REGISTERING PRINTING PLATES Filed June 23, 1936 9 Sheets-Shet B Oct. 31, 1939. w. F. HUCK 2,177,653

METHOD AND MEANS FOR REGISTERING PRINTING PLATES I Filed June 23, 1936 asheets-sheet' *9 l NQ I Patented Oct. 31', 1939 METHOD AND MEANS FOR REGISTERING PRINTING PLATES I William F. Huck, Richmond Hill, N. Y., assignor to R. Hoe & 00., Inc., poration of New York New York, N. Y., a cor- Application june 23, 1936, Serial No. 86,884

29 Claims.

This invention relates to a method and means for registering and trimming printing plates and more particularly stereotype or electrotype printing plates for multicolor and other printing in which accuracy of register is required.

Heretof ore, in registering and finishing a set of printing plates to produce an image or design in multicolor, it has been a common practice to produce register or index marks on the marginal portion or. trimming margin of the plate, which marks were located with respect to the matter on the plate and also an edge of the finished plate, so that after the margin was trimmed from the plate,

all the plates of the set were registered with relation to a selected edge thereof. This method of registering the plates is satisfactory when all the plates of the set are of exactly the same size, and all the images or designs on the plates have the same dimensions and the image or corresponding portion thereof on each plate bears the same relation to the edge of the plate as the image or corresponding portion thereof in each of the other plates in the set. This desired accuracy is seldom attained, and, since each plate of the set of plates is registered with relation to one edge thereof, it is ananifest that any inaccuracy in the plate or image dimensions will manifest itself in full dimension in a portion of the printed image.

Therefore, an object of this invention is to provide a method and means with which the conventional cruciform register marks or indices are located on .the marginal portion or trimming margm of the plate but with accurate relation to the image, design, or matter on the plate and also with accurate relation to the center of the plate, and

then trimming or cutting the four edges of the plate along lines located with respect to the register marks, and, consequently, the image and center of the plate, so that in registering a set of I plates for producing a multicolor image or design,

a given portion of the image or design on each plate of the set will be positioned with the same relation to its edges as the corresponding portion of the image or design on the other plates of the 5 set. Consequently, any inaccuracy that may occur in the production of the finished plate will be reduced as much as one half, because the register of the plate is determined with relation to its center rather than a selected edge.

Another object of this invention is to provide a method and meanswith which the conventional register marks or indices are located on the trim- .ming margin on the plate in accurate relation to the image or design thereon and also in accurate 55 relation to the plate center, and notching opposed marglns of the plate at points located with accurate relation to the register marks and, consequently, the plate center and image or design, and then employing the notches to accurately locate the plate in a plate bending mechanism incorporating a novel plate receiving receptacle or holder. A further object of this invention is to provide a method and means with which the conventional register marks or indices are located on the marginal portion of the plate in accurate relation to 10 the image or design thereon and also in accurate relation to the plate center, or to a determined point adjacent the plate or image area center, notching opposed marginal portions of the plate at points located with accurate relation to the reg- 15 ister marks and, consequently, the plate center and image or design, employing the notches to accurately locate the plate in a plate bending machine to bend the plate to arcuate or semi-cylindrical form, and then employing the notches in 20 locating the arcuate plate in accurate axial relation on the saddle of a plate trimming mechanism. Another objectof this inventionis to provide a method and mechanism with which 'the conventional register marks or indices are located on the 25 marginal portion of the plate in accurate relation to the image or design thereon and also in accurate relation to the plate center, or determined adjacent point, notching opposed marginal portions of the plate at points located with accurate 30 relation to the register marks and, consequently, the plate center and image or design, employing the notches to accurately locate the plate in a plate bending machine to bend the plate to aruate or semi-cylindrical form, and then employing the 35 notches in locating the arcuate plate in accurate axial, relation on the saddle of a plate trimming mechanism, and adjustably locating and locking the arcuate printing plate circumferentially onthe saddle with relation to the register marks, and, 40 consequently, the center of the plate, and then trimming the four edges of the plate along lines located with relation to the plate design and center of the plate.

It is an object of my present invention to provide an improved electrotype or stereotype printing plate finishing mechanism of generally improved construction, whereby the device will be simple, durable, accurate, and inexpensive in construction, as well as convenient, practical, serviceable and eflicie'nt in its use.

With the foregoing and other objects in view, which will appear as the description proceeds, the inventionresides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood that various changes in form,

' proportion, and minor details of construction may portion of the plate notching mechanism, but in a difierent opwith its components depicted erating position;

Figure 3 is a plan view of the plate notchin mechanism, parts appearing in section, the direction in which the view is taken being, indicatedby the arrow 3 in Figure 2; p

' Figure 4 is a fragmental end view of the plate notching mechanism, portions being broken away,the direction in which the view is taken being indicated by arrow 4 in Figure 1;

Figure 5 is a vertical sectional view of the plate bending mechanism, parts being broken direction indicated by the. arrow Ill. of Figure 9;

Figure 6 is a fragmental plan view of the flexible plate holder and notched plate, the view being taken in the direction indicated by the arrow -6 in Figure 5;

Figure 7 is an end elevation of the improved plate trimming mechanism;

Figure 8 is a longitudinal vertical sectional view taken on the line 8-4 of Figure 7, portions, being broken away;

Figure 9. is a fragmental vertical transverse sectional view taken on the line 8-9 of Figure 8;

Figure 10 is a fragmental elevation,- parts appearing in section, the view being taken in the Figure 1-1 is a fragmental longitudinal vertical sectional view, p rts appearing in elevation, de-.

picting the mounting for the plate-supporting saddle and plate-locating and adjusting mechanism;

Figure 12 is a substantially horizontal transverse sectional view taken on the line 12-12 ofFigure 8;

Figure 13 is.a fragmenta'l detailed plan view of a plate-trimming saw supporting mechanism, the view being taken in the direction indicated v by arrow 13 in Figure 7;

Figure 14 is an elevational view of 'a portion :of the printing plate, the removed trimming margin being indicated in dotted lines;

7 Figure 15 is a detailed transverse sectional view, parts appearing in elevation, depicting the relative position of the printing plate, plate 10- cating and adjusting lever, and the trimming -saw for removing the straight axial margin from the plate? Figure 16 is a fragmentai end elevation of-a modified plate-trimming mechanism;

Figures 170,171), 17c, 17d and 17a are diagrammatic views depicting the various stages in 'mysimproved method for finishing printing D Figure 18 is a diagrammatic view depicting the relative positions of images or image components in superposed plates of diiferent sizes where, the r relation of the plates is determined with relation to an edge or edges of-the plates,

and

Figure 19 is a similar view depicting the-relative positions of images orimage components in superposed plates of diiferent sizes where theregisterlng relation of the plates is determined with relation to a determined point located at or near the center -of the plate.

Referring to the drawings in which similar reference characters designate corresponding parts, there is depicted a mechanism for notching, bending and trimming electrotypeor stereotype printing plates, and this mechanism may be incorporated in a single frame, or, if' desired, .the mechanism for carryingout my invention may be supported by separate frames. It is to be understood, however, that the disclosed invention is directed to mechanism and method for trimming stereotype or electrotype printing plates so that the finished edges of each plate will accurately bear definite relation to the center of the plate and also the design or printing matter appearing thereon. 1

Plate notching Referring to Figures 1 to. 4, there is depicted a mechanism for carrying out a phase of my invention,'which mechanism includes a frame 20 having a bracket 'or platform 21 bolted or suit-. ably secured thereto, and spaced levers 22 are rigidly secured to a transversely extending shaft 23 rotatably supported in bearing ears or lugs 2 extending downwardly from the platform 2|. The intermediate portion of each lever 22 is pivotally connected with'the lower terminal of a link 25, as indicated at 26, and the upper terminal of each link 25 is pivotally connected to a lever plate 21, as indicated at 28, and the lever plate 21 is in the form of a relatively broad flat member, as best seen in dotted outline in Figure 3. In order ,to insure that the lever plate 21 is rigidly supported to move about a;

horizontal axis, one terminal of' this lever 21 is pivotally secured to fixed lugs 30, as indicated at ll, upstanding from the platform 21 at spaced points, and best seen in Figures 1 and 3. Theouter terminal of the'lever plate 21 is pivotally secured at opposed points, as indicated at '22, to ears or brackets 33, which extend downwardly from a plate-supporting table 25, asbest shown in Figures 1 to 3. Spaced links 26 are pivotally secured to ears 24 which extend downwardly from a portion of the table "which is remote from the ears 33,'and the lower terminal of each link 36 is pivotally secured to a lever 22 by bolts ,or other suitable securing device/as indicated at 31. :One of the levers 22 extend outwardly beyond its pivot 31, and is pivotally secured to a link 38, as indicated at All, and the lower terminal of the link 38 is. operatively secured to a treadle 4i pivotally supported, as indicated at 42, by abracket. upstanding from the machine frame 20. Inasmuch as the construction'of *the treadle is of conventional and well known form, the connection between the lower terminal of the link 28 and the treadle 41 is not illustrated except for the illustration given in Figure 1. A rod 44 is pivotally secured to the lever plate 21, as indicated at 45, and the lower-terminal of this rod extendsthrough an aperture 46 formed in-the machine platform 21, so that the rod 44 is slidably received therein. In order to bias the plate lever 21 upwardly or away iromthe platform 2l,'a helical spring- 41 is-positioned on therod M, and-its opposed terminals engage the platform 21 and a collar 53 carried by the rod 45.

From the foregoing it is manifest that by depressing the 'treadle II, the link 38 is moved downwardly, thereby. moving the levers 22 downwardly about their fulcrum 23. As the outer terminal of each lever 22 moves downwardly, it pulls downwardly on the links 35 and the table 35 The downward movement of the levers 22 also moves the links 25 downwardly, which, in turn, move the lever plate 21 downwardly about its fixed fulcrum 3| against the tension or bias of the spring 44. As the outer terminal of the plate lever 21 moves downwardly, it also pulls downwardly on the ears 33 and table 35, and by referring to Figures 1"and 2, it will be seen that the leverage ratios in the levers 22 and 21 are so proportioned that as the levers 22 move downwardly about their fixed fulcrum 23, and the lever 21 moves downwardly about its fixed fulcrum 3!, the table35 is moved downwardly so that it is maintained in substantially horizontal position throughout the amplitude of its movement. When the treadle H is released, the spring 41 forces the components of the table actuated mechanism upwardly, thus returning the plate to its uppermost position, and the reason for moving the table upwardly and downwardly in a horizontal position will be hereinafter disclosed.

It is well known and understood by those skilled in the art that each plate in a series of printing plates for producing a multicolor image or design is suitably marked with register indices to aid in trimming the plate in order to obtain accurate registration of the superposed colors in producing the multicolor image. These register indices are usually cross marks positioned in the marginal portion of each plate, and are located,

with relation to an edged the plate or design or printed matter appearing thereon. Applicant produces the. usual cruciform register marks or indices M on the marginal portion of the plate P, as shown in thediagrammatic Figures 170. and 17b, but these marks are locatedwith relation to a predetermined point on the plate or the center of the plate and the matter appearing on the plate. Therefore, since the register marks or indices are located with relation to the center of each plate, and the plate then trimmed along lines located with relation to the register marks, and, consequently, center of the plate, it is manifest that the four finished edges of the plate will be accurately located relative to the center of the plate as well as the images thereon. Any preferred means may be resorted to for producing and locating the register indices M in the marginal portions of the plate, but a convenient method is found in placing cruciform registering marks M in the longitudinal margins of the plate at points coinciding with a line passing transversely through the center of the plate, and also positioning a cruciform mark M in the transverse or side margin ofthe plate at a point coinciding with a line passing longitudinally through the center of the plate, as best shown in Figure 17a. Thus it is seen that although the cruciform register marks or indices M are positioned in the trimming margin of the plate, they have been located with relation ,to the center of the plate, for reasons tobe hereinafter more fully disclosed.

Spaced magnifying glasses or microscopes 55 of conventional design are supported by brackets 5| secured ''to and upstanding from the frame or platform 2|. These magnifying glasses, as

will be hereinafter disclosed, are employed to sight and locate the register indices, so that the printing plate P may be properly located on the table 35,,and, in most instances, two glasses will suffice to properly locate the plate. In Figures 1 and 2 of the drawings, two glasses have been illustrated, although it is to be understood that, if desired or required, three glasses may be provided, the third glass being employed to sight the register marks formed on the transverse edge of the plate. The magnifying glasses 5!! have been depicted in the accompanying drawings as be ng supported by fixed brackets 5|, but, it is to'be understood, that in order to accommodate different size plates, the glasses 55 may be supported by adjustable brackets which may be adjusted to move the glasses towards the center of the table 35 when smaller plates are employed.

upstanding lugs 52 disposed at right angles to each other and having threaded apertures formed therein for the reception of threaded adjusting screws 53. By this arrangement two adjusting screws engage each corner of the plate P, and by manipulating the enlarged knurled heads 55 of the screws 53, the plate P may be adjustably moved on the table 35 until the cruciform register indices thereon aline with the hair line sighting marks or indices provided in the microscope or magnifying glasses 50, and when these-register indices of the plate and hair line marks are in proper register or alinement it is then known that the plate is accurately positioned on the table in definite relation to its register marks, and, consequently, the center of the plate or selected point on the plate.

A rotary cutter or saw 55 is secured to a shaft 51 rotatably mounted in suitable bearings 58 supported by the machine platform 2|. A saw is located adjacent each end of the table 35, and the table is provided at each end with a slot 55 to permit the saw to pass therethrough, for reasons to be hereinafter disclosed. A'pulley or sprocket 5| is secured to the outer terminal of each shaft 51, and a chain or belt 82 is trained around each pulley orsprocket. The lower portions of the chains or belts 62 are trained around drive pulleys or sprockets 3, best shown in Figures 1 and 2,

.and these drive pulleys or sprockets are operapearing at the left of the machine isrotated in counterclockwise direction, and the saw at the right of the machine is rotated in clockwise direction. The saw-driving mechanism may be suitably housed for the protection of the operator, but, inasmuch as such housing mechanism is common and well known to those skilled in th art, it is not here illustrated. 1 i

In order to protect the-operator from injury by the cutters and to guard against flying chips striking the magnifying glasses, guards 5'! are provided and are secured to members 55 which are loosely journaled on the shafts 51. The members 68 are provided with arms 63 secured to and extending downwardly from each of the guards 61, as best shown in Figures 1 and 2. Brackets 15 extend downwardly from the table 35, and each bracket has a roller ll rotatably supported in its outer or lowermost terminal for cooperative engagement with the arm 63', so that as the table 35 is lowered the rollers ll force the arms 53 outa the saws, thesaw guards 88 being counterwardly, thereby rocking the saw guards 81 over weighted to maintain the arm 88 in engagement with the rollers 1|.

In the operation of the plate notching mechanism the plate P isplaced'upon the table 35, and then the plate adjusting screws 53 are manipulated until the cruciform register indices M marked on the plate are moved to accurate alinement with the hair line sighting-indices provided in the magnifying glasses or microscopes 58. After the plate P has been accurately positioned on the table 35 by meansof the microscope and adjusting screws 53, these screws are tightened to maintain the plate in this position, and then the treadle II is depressed. As the treadle 8| moves downwardly, the plate P moves downwardly into engagement with the rotating saws 56, thereby cutting register or locating notches 12, best shown Plate bending After the locating or register notches 12 have been formed in the plate P, the plate is then positioned, as shown in Figures 5 and 6, in a platereceiving receptacle or holder 13 having a flexible sheet metal backing 15 and marginal flange 18. The plate holder 13 is-shaped to receive the plate P, and this holder is provided at its'leading end with a fixed arcuate stop member -or block 11, which is rigidly secured to the backing 15, by

screws or other suitable securing devices 18, and

a yieldable arcuate stop member 88 is slidably secured tothe opposed or trailing terminal of the plateholder 13 by screws or rivets 8|, which extend through slots 82 formed in the yieldable stop 88 and are secured to the backing 15. In order to bias the yieldable stop member 88 towards the leading terminal of the plate holder 18, leaf springs 83 are suitably secured to the yieldable stop 88- and engage the rear flange 18. when the plate P is positioned in the plate holder 18, its notches 12 are engaged by tongues or projections formed on the fixed and yieldable stop members 11- and 88, respectively, thus accurately positioningthe plate ,P in the holder 13 preparatory to its bending operation. The plate-bending an adjusting screw 9| which is swiveled in the bracket 98 and threadedly engages the carriage 88, so that by rotating the screw, the rollers 81 may be moved towards or away from the large roller 88 to properly accommodate the plate and its holder. An arcuate or spirally-shaped platesupporting or receiving-bracket 82 is secured to the machine 'frame 84', and its plate-supporting portion defines an arc of greater radius or radii than the periphery of the bendingroller 88. A

table 01" platform 18 is secured to the frame 88, .and is positioned to support the plate holder 18 in its initial or plate receiving position. The roller 88 is driven from any suitable source of power, not shown, in conformity with the usual practice, and as this roller is rotated counterclockshape, the driving mechanism. is stopped by a conventional limit switch or stop mechanism, not shown, so that the plate is supported between the roller 88 and bracket. in position to be conveniently removed from the machine.

By this arrangement the fingers 85 of the fixed and yieldable stop members 11 and -88 engage the notches 12 of the plate P, thereby accurately locating the plate in the receptacle or holder 18 to insure the accurate bending of the plate with its notches '12 positioned in the straight axial edges of the bent plate, and, since the notches have been located with relation to the register indices, it is manifest that these notches may be employed in the trimming operation to aid in locating the bent plate in the trimming mechanism, as will be hereinafter more fully disclosed. Since the notches 12 are accurately located with relation to theregister indices marked on the plate P, the engagement of the tongues 85 with the notches 12 aline the plate in its holder 18, so that the longitudinal edges of the plate are perpendicular to the axes of the bending rollers 88 and 81, consequently, assuring that after the plate is bent, its notches 12 will be positioned in edges that are disposed in accurate axial relation to the arcuate plate.

Plate trimming In order to accurately trim or shape the plate P after it has been notched and also bent to semi-cylindrical form to conform to the printing cylinder periphery, a trimming mechanism, best shown in Figures 7, 8, 9, 10, 11, 12, 13 and 15, is provided, and it includes a frame 85 of any preferred configuration to best support-the operating components of the device, and a cylindrical shell or tube 98 extends longitudinally of the machine frame and is rotatably supported in spaced antifrictionbearings 81 and 88 suitably supported by the machine frame, the bearing 88'may also serve, in a measure, as a thrust bearing to prevent longitudinal movement of the shell 88 relative to the machine frame 85. An

arcuate or semi-cylindrical saddle I88 is supably support a shaft I82 which extends axially through the shell 88, and a worm wheel 188 is keyed or otherwise secured to the outer terminal of the shell 88, as best shown in Figure 8 of the drawings. A worm I85 extends transversely of the machine and is rotatably supported in spaced antifriction bearings I86, best shown in Figure 7. This worm I85 is driven from an electric motor" secured to the shaft of the motor I01, and a chain or belt III which is trained around the sprockets I08 and H0, the motor I01 being suitably secured to and supported by the machine frame, as shown in Figures land 8. Gear teeth are cut into spaced portions of the shaft I02, as

best shown in Figure 8, to define drive pinions function as both radial and thrust bearings, and

the opposed end of the shaft is rotatably mounted in roller bearings II9. A pinion I20 is secured to each shaft III and meshes with' the gear II3, so that, as the shaft I02 is rotated, power is imparted to each shaft II'I through the pinion H2 and gears H3 and I20. A beveled circular cutter or saw I2I is secured to the outer terminal of eachshaft III for engagement with the arcuate circumferentialedges of the printing plate P, as will be more fully disclosed hereinafter. Each housing H6 is secured to and moves with the cylindrical shell 96, so that,,as the shell 96 is rotated about its axis, the housing II6 moves in an arcuate path of travel about the axis of the shell 96, so that the circular cutters I2I will follow the circumferential arc of the plate P. Therefore, when the motor M1 is energized, it imparts power to its sprocket or pulley IIO, belt or chain III, sprocket or pulley I08, worm I05, and worm wheel I03, thereby rotating or oscillating the casing 96 and housing II6, so that the circular cutters I2I accurately trim the arcuate margins from the plate to produce accurately located arcuate beveled edges, as will be more fully disclosed hereinafter. While the cutters I2I and their supporting housing H6 and the cutter driving mechanism are depicted in Figures '7 and 8 as being in the upright intermediate position, it is to be understood that this is the; position occupied by these components when the cutting operation is approximately half finished, and that their normal inoperative position is at a lower portion of their arcuate path of travel, at a point where the circular cutters I2I, are not in engagement with the arcuate printing plate positioned on the saddle I 00. In order to drive the shaft I02 to thereby impart motion to the circular cutters I2I, an electric motor I22 is supported by the machine frame, as 'best shown in Figure 8, and this motor imparts power to the shaft I02 through a grooved pulley I23 carried by the shaft of the motor I22, and a grooved pulley I25'secured to a reduced extension I26 of the shaft I02, and preferably V-shaped belts I21 which are trained around the pulleys I23 and I25. Although belts and pulleys motor I22 to the shaft I02, it is, of course, to be understood that chains or sprockets or other suitable power imparting instrumentalities may be employed.

In order to adjust the notched semi-cylindrical printing plate P upon the saddle I to insure the proper location of the plate relative'to themarginal trimming cutters or saws, preparaotry to cutting or trimming the margins from the plate, the plate is first placed on the saddle I00 and positioned so that each notch 12 formed in its straight axial edge is engaged by an alining finger or lug I28, formed at the free or outer terminal of a lever I30, which is fulerumed to a bracket I3I, secured to the saddle I00, there being a lever I30 positioned adjacent each axial edge of the plate P, as best shown in Figures 7 and 17c of the drawings, and one of the levers I30 is shown in detail in Figure 15. The outer terminal of a toggle link I32 is pivotally secured to each lever I30, as best shown in Figures '7 and 11, and the opposed terminals of the toggle links I32 are pivotally united and securedto a lever link I33, as indicated at I34, and the intermediate portion of the lever link I33 is pivotally secured to a lever arm I35, as indicated at I36. One terminal of the lever arm I35 is fulcrumed to the machine frame or any convenient bracket thereof; as indicated at I31, and its opposed or movable terminal is pivotally secured to a rod or link I38, as indicated at I40. The lower terminal of the rod or.link I38 is pivotally secured to a treadle I, as indicated at I42, and the treadle, in turn, is fulcrumed to the machine frame, as indicated at I43, and shown in Figure '7 of the drawings. A shaft I45 extends longitudinally of the machine frame and is rotatably mounted in suitable bearings I46 carried by the frame, as best shown in Figures 7, 8 and 11 of the drawings. The outer terminal of this shaft has an operating handle I" secured thereto, and its intermediate portion has an arm I48 keyed or otherwise rigidly secured thereto, and the outer terminal of the arm I48 is pivotally secured to a link I50, as indicated at I5I. This link I50, in turn, has its opposed terminal pivotally secured to the lower end of the lever link I33, as indicated at I52.

In order to move the locating fingers or lugs I28 of the levers I-into engagement with the registering or locating notches I2 of the printing plate P, the treadle I is depressed, thereby moving the link I38 and lever arm I upwardly. The upward'movement of the lever arm I35 about its fulcrum I3] moves the lever link I33 upwardly, thereby imparting upward and outward movement to the toggle links I32, which, in turn, swing the levers I30 upwardly about their fulcrums until their locating flngers I28 enter the notches I2 of the printing plate P. When I00 and correctly positioned axially by the engagement of the locating fingers I28 with the notches I2 of the plate, the plate may then be temporarily held on the saddle by a mechanism whichincludes a bell crank lever I58 having a manipulating handle I55, and the lever I53 is fulcrumed to a plunger rod I56, as indicated at I5'I. An enlarged head I58 is formed on or secured to the rod I56, and the shank I60 of a cushioned shoe I6I is secured to the head I58 by a tubular nut I62 which clamps a ball or enlargement I63 formed on the inner terminal of the shank within a socket formed in the enlarged head I58. The cushioned shoe IN is normally biased towards the saddle I00 by a helical spring I65 which surrounds the rod I56, and one terminal of the spring engages the enlarged head I56 and its opposed terminal engages the end wall of the cylindricalhousing I66 in which the rod I56 and enlarged head I58 are slidably mounted. When the handle I55 is moved downwardly to the position shown in Figures 8 and 10, the spring I65 forces the cushioned shoe I6I into engagement with'the printing plate P, and exerts sufficient stress against the plate to hold it on the saddle I 00.

In order to position the plate P in accurate relation circumferentially of the saddle, the handle I41 is moved thereby rocking the shaft I45, which, in turn, moves the arm I48 about the fulcrum shaft I45. The movement of the arm I48 imparts movement to the .link I50, which, in

turn, rocks the lever I33 about its fulcrum I36,

thereby moving one of the levers I30 downwardly and the opposed lever I30 a corresponding distance upwardly, thus rocking or adjustably moving the plate P eircumferentially on the saddle While the plate P is being adjusted circumferentially on its saddleI00, the treadle I4I may be depressed, thus causing the levers I30 to press upwardly against the axial edges of the printing plate P, to oppose the pressure of the cushioned shoe I6I,'thereby slightly lifting the plate P from the saddle 100 thus permitting the plate to be more easily moved clrcumferentially on the saddle. In order toaccurately position the plate P circumferentially on its saddle I00, a magnifying glass or microscope I61, shown in Figure 8 of the drawings, is employed to observe the position of the register mark M positioned on an arcuate margin of the plate P, and, in sighting the register mark M through the microscope or magnifying glass I61, the circumferential component of the cruciform register mark M is not considered, but the axial component is accurately alined with the hair line in the microscope, thus accurately indicating the correct circumferential position of the plate P on the saddle I00.

After the plate has been accurately located,

both axially and circumferentially, on the saddle I00, it may be securely clamped to the saddle by a mechanism, best shown in Figures '7, 8, 9 and 10. This mechanism includes a transversely extending shaft or rod I68 which extends through a slot 110 formed in the enlarged plunger head I58, vand a suitable manipulating wheel or handle IN is secured to each terminal of the shaft I68. Portions of the shaft I 68 adjacent the hand wheels "I are threaded, as indicated at I12, and these threaded portions of the shaft extend through nuts I13 pivotally secured to the outer arms I14 of bell crank levers I15 whichare'fulcrumed on spaced shafts I15 supported by brackets 85' forming components of the machine frame 95. Eachbell crank lever I15 has spaced diversion arms I16, and the innermost terminals I11 of the arms I16 are provided with alined bores or apertures for the reception of a stub shaft I18. The opposed terminals of each stub shaft I18 are received within and suitably secured to bosses I formed on the outer terminals of flanges I8I extending upwardly from an arcuate clamping foot I82. Felt or other suitable cushioning material I83 is positioned on the inner arcuate face of each clamping foot, and is secured thereto by suitable clamping bars or straps-I84 received within grooves formed in the arcuate face of the foot I 62, and these clamping bars I84 are secured to the foot by flat-headed screws I85 so that the bars securely bind the felt strapvto the foot. The marginal portions-of the felt cushion is clamped to the edges of the foot by suitable clamping bars or straps I84. In order to yieldingly maintain the components of the plate clamping mechanism in predetermined position, spaced helical springs I86 surround the unthreaded portion of the rod or shaft I68, and one terminal of each spring engages a collar I81 suittate the shaft ably secured to the rod I68, and the opposed ter minal of each spring I86 engages theenlarged plunger head I 58,- as, best shown in Figure 9. The springs I86 exert equal stress in opposed directions on the rods I68, thus maintaining the components of the clamping device in predetermined relation to-the plate supporting saddle I80. When it isdeslred to securely clamp the printing plate P on the saddle I00, the convenient one of the hand wheels I is manipulated to ro- I68. The rotation of the shaft I68 causes the nuts I13 to feed outwardly along the shaft, thereby causing the bell cranks I15 to move the clamping feet I82 into engagement with the outer surface of the printing plate P, thus securely binding the plate in correct position on the saddle. If one clamping foot I82 engages the plate P in advance of the other, then a spring I86 will yield to permit the rod to impart equal stress to both feet I 82 through the interposed bell cranks I15.

After looking the plate P on the saddle, all four edges thereof may then be cut or trimmed to accurate predetermined dimensions to produce beveled edges to be engaged by suitable plate clamps carried by the printing cylinder, as will be hereinafter more fully disclosed. In trimming the arcuate edges of the plate, the motors I01 and I22 are energized, thus driving the circular cutters I2I, and also moving the cylindrical shell 96 and saw supports or housing II6 about the axis of the shaft I02, which also coincides with the axis of the semi-cylindrical plate supporting saddle I00, thus causing the saws I2I to travel in accurate paths coinciding with the arcuate edges of the supported plate to cut away the marginal portions of theplate and produce arcuate beveled edges which are accurately located relative to the center of the plate. 1

In order to trim the straight axial edges of the plate, cutting or sawing, and supporting mechanism therefore, is provided, which mechanism includes a rail I88 supported at each side of the I machine frame 85 by brackets or braces I80, best shown in Figures 7 and 13 of the drawings. Each rail I88 extends longitudinally of the machine, and its upper and lower longitudinal edges are machined to define opposed accurately-dimensioned guideways or tracks I8I. A saw or cutter supporting carriage I92 is provided for movement longitudinally along each rail I88, and each carriage includes a substantially U-shaped frame I83 which extends partly around each rail I88, and spaced rollers I95 are rotatably secured to the frame I93, by screws or other suitable securing or supporting means I86, to engage the upper and lower horizontal edges of the guideways or tracks I9I, and similar spaced rollers I81 are rotatably secured to and supported by the frame I83 on short shaft' members or screws I98, which rollers engage the vertical machine surfaces of the tracks I9I at points adjacent their upper and lower terminals. By this arrangement the carriage I92 is mounted for free movement along the tracks I 9| of the rail I88, and inasmuch as the tracks I8I and cooperating rollers I95 and I91 are accurately machined .to close tolerances, the carriage I82 will move accurately in parallelism with the axis of the plate supporting saddle I00 and supported plate P. An electric motor 200 is suitably secured to a supporting block 20I which is mounted for vertical sliding move drawings.

Each electric motor 200 drives a beveled saw or cutter 208, as best shown in Figures 7, 8 and 13, and in order to adjustably move the saw or cutter 205 vertically relative to its carriage I92, and con-- sequently the plate supporting saddle I00, an adjusting screw 208 is swiveled in a boss 201 extending inwardly from each carriage frame I03, and the lower terminal of each screw 208 is threaded in a motor supporting block 20I, as indicated at 208, and best seen in Figure 7 of the Inasmuch as the adjusting screw 208 is swiveled in the lug 201 and held against longitudinal motion relative thereto, it is manifest that by rotating the adjusting screw 206, the motor supporting block 20I, motor 200 and saw 205 are moved vertically; so that the saw 205 is brought into accurate relationship with the straight axial margin of the printing plate, for reasons to be hereinafter set forth. After each saw 205 has been correctly adjusted relative to an axial margin or edge of the printing plate, its motorsupporting block 20I may be locked against move: ment relative to the carriage frame I93 by a screw 2 I which'extends through an aperture formed in the carriage frame I93 and is threaded into the motor supporting block 20I, as best seen in Figures '7 and 13 of the drawings. In order to gain access to each screw 2I0, an aperture 2 is formed in the rail I88, so that a wrench or other suitable tool may extend therethrough for engagement with the head of the locking screw 2 I 0.

It is preferable to move the cutters or saws 205 and their drive motors 200 relatively slow along their path of travel during the cutting operation, and to return them to their original or starting position at an accelerated speed. This is accomplished by the provision of a driving mechanism which includes a relatively large gear 2I2 rotatabiy supported on antifriction bearings 2 supported in a housing 2l3 carried by the machine frame 95, and a pinion -2I5 meshes with the gear 2I2, the pinion being driven by an electric motor 2I6, best seen in Figure 7 of the drawings, and the pinion 2 I5 is rotatably mounted in antifriction bearings supported, bythe housing 2I3, as best shown in Figure 12. A lever arm 2" is keyed or otherwise secured to a shaft 2I8 which extends transversely across the machine and has a relatively long am 220 keyed or otherwise secured to each terminal, so that the lever arm 2", shaft 2I8 and long arms 220 move about the axis of the shaft 2I8 in unison. The arm 2" is provided with an elongated guide opening or slot 22 I, as best seen in Figure 12 of the drawings, and an accurately machined guide way or surface 222 is formed at each side of the slot 22I and extends longitudinally thereof. A spindle or stub shaft. 23 is suitably secured to the gear 2I2 by a nut or other suitable securing device 225, and spaced antifriction bearing members 228 are carried on the stub shaft 223 and arranged so that one bearing member engages each guide way 222. A link 221 is pivotallysecured to the outer terminal of each arm 220,'and the op- Posed terminal of each link 221 is pivotally secured to a carriage frame I93, so that movement of the arms 220 will cause the carriages I92 to move along the supporting rails I88.

In trimming the straight axial edges of the plate P, the motor 2I6 is energized, and this motor drives the pinion 2i! which rotates the gear 2I2, and, as the gear 2I2 rotates, an antifrlctiton member 226, by engaging a guide way 222 of a slot 22I, causes the lever arm 221 to rock ina of the saws.

counterclockwise direction, as viewed iniFigure 8. As the arm 2I'I moves, corresponding movement is imparted to the arms 220, which, in turn, draw the saw-supporting carriages I92 along the guide tracks I9I of the supporting rail I88, thereby moving the spaced saws or cutters 208 along the opposed straight axial margins of the plate, so that these margins are trimmed from the plate to produce accuratey located beveled edges for engagement with suitable plate clamping means when the plateis'clamped in printing position on the form cylinder of the printing machine. In advancing the saws or cutters 205 during their cutting operation, an antifriction member 226 engages a guide way 222 of the arm 2" during the advancing movement of the large gear 2I2 through an arc of travel greater than 180, and through an arc of travel less than 180 during the idle return movement Thus it is manifest that the saws are advanced relatively slow during their cutting operation, and that their return movement is accelerated.

In order to insure safety of operation and also maintain definite sequence of operation of the various operating components of the plate trimming mechanism, electric interlocks of conventional form may be provided so that the motors can not be started-until the plate is locked .in position on the saddle I00, and the locating members are disengaged. This interlocking system may also include limit switches to stop the motors when the cutting cycle is completed, and the circuits may be interlocked to avoid inter ference between the cutters which cut the straight axial edges of the plate and those which cut the curved circumferential edges. Inasmuch as electrical interlocks of this type are well known and understood by those skilled in the art, and are not a specific part of this invention, they have not been illustrated.

From the foregoing it is manifest that applicant has provided method and means for producing a set of printing plates for multicolor or other printing in which each plate will be identically the same size as the other plates in the set, and, in which, the image will bear the same relation to the edges of the plate as all plates of the set. Applicant has also provided method and means for locating the conventional register marks relative to the center of the plate, and then accurately finishing the entire plate with relation to its center so that any errors or inaccuracies due to variation in plate ben ding or matrix shrinkage or other causes will be only one half as great as where the registering is done from ,an edge or a point near the edge of the plates, which was a common practice prior to my invention.

In employing these plates in printing, it is intended to provide printing cylinders with individually adjustable clips to engage all four edges of the plate, and the clips for two adjacent edges will be marked wtih relation to the in the art and is not a specific element of my alines with the register mark or index M formed present invention apart from .the method and mechanism disclosed, the plate clip arrangement is not illustrated.

In Figure 16 a modified plate trimming mechanism is disclosed, which is similar to the device depicted in Figures '7 and 8, but which is con-'- structed and arranged to accurately position a semi-cylindrical printing plate upon its semi-0y lindrical saddle I00 without forming'notches in the straight axial edges of the plate P. Its plate adjusting levers I30a are similar to the levers I30 except the notch engaging fingers or lugs have been omitted so that the outer terminals of the levers I30a engage the straight :axialedges of the plate, thereby movably adjusting the plate P on the saddle I00, sothat it may be accurately located circumferentially on the saddle by observing the register mark formed on the curved margin of the plate in themanner hereinbefore disclosed. Inasmuch as the register or locating notches are not formed inthe axial edges of the printing plate P, it is necessary to correctly position the plate axially on the saddle by observing register marks or indicesproduced thereon. In this form, the plate is provided with register marks M in its margins at the center of the top of the plate and at'the' center of the bottom and also at the center of one side. These marks may be the usual cruciform marks M, shown in Figure 17a, or they may be simply straight lines,

scopes 230 are provided, and these glasses aresupported by brackets {3| suitably secured to the machine frame. Each magnifying glass 230 is positioned so that its sighting register mark on the straight axial edge of the plate P when the plate is located in accurate axial position on the saddle. By this arrangement the plate may be accurately located both axially and circumferentially on the saddle without forming axial locating notches in the plate.

It will be understood that the invention may be embodied in other specific forms without departing .from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, and it will be further understood that each and every novel feature and combination present in or possessed by the mechanism herein disclosed forms a part of the invention included in this application.

In preparing a set of plates for producing a multi-color image, the plates are cast in a mold in which each casting matrix is secured in predetermined position. In order to insure that all the plates in the series accurately register in the printing operation, the matrices for producing these plates are registered in exact relation to one another by means of register racks well known to those skilled in the art, and a preferred form is disclosed in the United States: Patent No. 2,011,584. The key matrix is squared in the rack by means of marks accurately located on the ma'- trix and wires stretched at'right angles across the rack frame so that the point of intersection of the cross wires indicate the approximate center of the matrix. A plurality of adjustable needle points are then moved to registration with selected portions of theimase appearing on the matrix, and with the needle points in this position, the trimming points of the 'matrix are indicated or cut by the rack. The key matrix is then moved, and with the needle points remaining in the position to 'which they were originally adjusted, the remaining matrices for producing other plates of the series are positioned one at atime in the rack withthe selected portion of the image located at the needle point, so that each matrix is located in the rack in exactly the same position as the key matrix to insure that all the plates are cast with their image producing portions located in accurate regi tering relation with each other. Suitable register indicating marks, as disclosed in this application, are formed in the matrix, and these marks are located with relation to a determined point located at or near the center of the matrix. In casting the plate'these marks are formed on each plate, and, are, of

course, located with relation to a point located at or near the center of the plate.

In producing printing plates attempts are made to produce each plate, in a series of plates, for printing an image in multi-color, exactly the same size as the remaining plates in the series.

It is not always possible, however, to produce all the plates in a series exactly the same size owing to temperature changes, variation in casting shrinkage; and other causes well known to those skilled in the art. Referring to diagrammatic Figure 18 of the drawings, 'there are depicted two plates in superposed relation with the uppermost plate shown smaller than the lower plate and the inadvertent difference in size of the plates being greatly exaggerated. A distance representing the difference in transverse dimensionsof the two plates is indicated at T, and the diiference in longitudinal dimensions of the two plates is indicated at L. These plates prior to the margin trimming operation have register marks cast thereon inconformity with the existent practice and located with relation to the upper and left located adjacent the top edges of the plate they are not oifset transversely any appreciable distance. The images 2, 5 and 4 are offset longitudinally a distance equal to half the distance L and the images 3, are offset longitudinally a distance equal approximately to the longitudinal distance L. Thus. it is seen that the images 5 located at the centers of the plates are offset both longitudinally andtransversely a distance equal to half the distances T and L, and the images 4 are offset transversely a distance approximately equal to the distance T, and the images 3 are offset longitudinally a distance equal approximately to the longitudinal distance L. From the foregoing it is manifest that when the register marks are located with relation to an edge or edges of the plateany inaccuracy in'the diiferent plates will result in offsetting the images which are located away from the register edges a distance equal to the difference in the sizes of the plates.

In Figure 19, there are depicted two plates of different sizes positioned in superposed relation 10 half the distance of the transverse dinerence T the longitudinal diiference L in sizes of the two plates. Thus it is seen that in employing applicants method of locating the register marksv with relation to a point located at or near the 15 center of the image producing portion of each plate, that the difference in size of the separate plates employed in printing the same image will result in offsetting the superposed color or image component only half the distanceoi an offset that i 20 would be produced by plates of similar diiierence in size and having their register marks located with relation to the edge or edges of the plate. Having thus described my invention, what I claim is:

' 25- 1.- The method of finishing a plurality of printing plates to produce an image in multicolor,

which consists in producing on each plate a pinrality or register marks accurately located with relation to a determined point located at or near 30' the center of the plate, and trimming the margins of the plate along lines located with relation to v the register marks. and consequently the said point so that all the plates are exactly the same size and the images thereon located in all direc- 5. tions from said point to have the same relation to the edges of the plate and the said point.

2. The method of finishing'a plurality of printing plates't'o produce an image in multicolor, which consists in producing on each plate a pluu rality oi register marks accurately located with relation to a determined point located at or near the center of the plate, forming locating notches in each plate positioned with relation to the register marks and the said point, bending each 5 plate to arcuate form with its locating notches in its axial margins, and removing the axial and arcuate margins of each plate at points located ,with' relation to the register marks and locating (notches and consequentlythe said point so that I 50 all plates are exactly the same size and the images thereon located in all directions'from said points to have the same relation to the said points and edges of all the plates.

3. The method of finishing a set of printing plates to produce a common image in a plurality of colors, which consists in producing a plurality of register marks'on each plate accurately located with relation to a determined point located at or near-the center of the plate, and trimming the margins of each plate along lines located with -7 at or near the center of the plate, bending the plate to arcuate form, and removing the axial and arcuate margins from the plate along lines located with relation tothe register marks and consequently the said point so that components 7 of the matter appearing on the plate are located accurately relative to said points in all directions therefrom.

5. The method of finishing printing plates for printing cylinders, which consists in producing a plurality of register marks on each plate ac- 5 curately located with relation to a determined point located at or near the center of the plate, forming locating notches in opposed margins of the plate and positioned with relation to the register marks and said point, bending the plate to 10 arcuate form with the locating notches positioned in the straight axial margins of the plate, and removing the axial and arcuate margins of the plate at points located with relation to the register marks and locating notches and consequently the said point so that components of the matter appearing on the plate are located in all direction from said point accurately relative to the said point and edges of the plate.

6. The method of finishing a printing plate having a marginal area and an image-bearing area, which consists in marking the marginal area 0! the plate with a plurality of indices accurately located with relation to a determined point located at or near the center of the imagebearingarea, and trimming the marginal area from the plate along lines located with relationto the indices and consequently the said point so that components oi the image are located in all directions away from said point,

'i-The method or finishing a printing plate having a marginal area and an image-bearing area, which consists 'inmarking the marginal area of the plate with a plurality of indices located with relation to a determined point located at or near the center oithe image-bearing area, bending the plate to semi-cylindrical form, and trimming the marginal area from the plate along lines located with relation to the indices and consequently the said point. 40

8. The method of finishing a printing plate having a marginal area and an image-bearing area, which consists in marking the marginal area'oi the plate with a plurality of indices 10- cated with relation to a determined point located at or near the center of the image-bearing area,

cutting regi'ter'notches in opposed margins of the plate at points located with relation to the indices and consequently the said point, bending the plate to semi-cylindrical form so that the notches are positioned in the straight axial margins of the plate, and trimming the marginal edges from the plate along lines located with re lation to the register notches and the indices and consequently the said point of the finished plate.

9. The method of finishing a set of printing plates to produce a common subject in multicolor, which consists in marking the marginal portions of each plate of the set with a plurality of indices accurately located with relation to a determined point at or near the center of the image-bearing portion of the plate, andtrimming the marginal portions from the plate along lines located with relation to the indices and consequently the said point or the plate so that the components of the image on each finished plate are located in all directions away from said point and bear the same positional relation to the said points and edges of the plate as the images on all the plates of the set bear'to the said points and edges.

10. The method of finishing a set of printing plates to produce a common subject in multicolor, which consists in marking the marginal termined point located at or near-the center of the image-bearing portion of the plate, bending each plate to semi-cylindrical form having.

straight axial margins and arcuate circumferential margins, and trimming the axial and circumferential margins from each plate along lines located with relation to the indices and consequently the said point so that the image on each finished plate bearsthe same positional relation to the said point and its edges as the images on all the plates of the set bear to the said points and edges.

11. The method of finishing a set of printing plates to produce a common subject in multicolor, which consists in marking the marginal portion of each plate of the set with a plurality of indices accurately located with relation to a determined point located at or near the center of the image-bearing portion of the plate, cutting register notches in opposedv margins of each plate at points located with relation to the indices and consequently the said point, bending each plate to semi-cylindrical form having straight .axial margins and arcuate circumferential margins.

with the register notches positioned in the straight axial margins, and trimming the axial and circumferential margins from each plate along lines located with relation to the indices and register notches and consequently the said point so that the image on each plate bears the same positional relation to the said point and edges as the images on all the plates of the set bear to the said points and edges.

12. Apparatus for finishing a printing plate marked with a plurality of register indices'accurately located with relation to a determined point located at or near the center of the plate, including means for accurately trimming the margins of the plate along lines located with relation to the register indices and consequently the said point so that matter on the finished plate is accurately located relative to the said point and edges of the plate. 1

13. Apparatus'for finishing a printing plate marked witha plurality of register indices accurately located with relation to a determined point located at or near the center of the plate, including means for bending the plate to semicylindrical form, and means for accurately trimming the straight axial margins and arcuate margins of the plate along lines located with relation to the register indices and consequently the said point so that matter on the finished plate is accurately located relative to the said point and its axial and arcuate edges.

14. Apparatus for finishing a printing plate marked with a plurality of register indices accurately located with relation to a determined point located at or near the center 01' the plate, including means for notchingopposed margins of the plate at points located with relation to the said point, means for bending the plate to semicylindrical form so that its notches are located in each straight axial margin of the plate, means for accurately trimming the straight axial. and arcuate margins of the platealong lines located with relation to 'the register indices and the notches and consequently the said point so that matter on the finished plate is accurately located relative to the said point and its axial and arcuate edges.; l

15. Apparatus for finishing a printing plate marked a plurality oi register indices aclocated in the straight axial margins of the plate, plate-trimming means having instrumen talities for engaging the notches to accurately locate the plate thereon so that the straight axial margins and arcuate margins of the semicylindrical plate are accurately trimmed along lines located with relation to the register indices and notches and consequently the said point so that matter on the finished plate is accurately located relative to the said point and its axial and arcuate edges.

16.Apparatus for finishing a printing plate marked with a plurality of register indices accurately located with relation to a determined point located at or near the center of the plate,

including means for accurately notching op-.

posed margins of the plate at points located with relation to the said point, plate bending means having instrumentalities for engaging the notches to locate the plate therein so that the plate is bent to semi-cylindrical form with the notches located in the straight axial margins of the plate, plate-trimming means having instrumentalities for engaging the notches to locate the plate thereon so that the straight axial margins and arcuate -margins of the semi-cylindrical plate are accurately trimmed to produce .beveled edges located with relation to the register indices and notches and consequently the said point so that matter on the finished plate is accurately located relative to the said point and its beveled axial and arcuate edges.

17. Apparatus employed in finishing printing plates having register indices marked thereon, including a horizontally disposed vertically-movable plate supporting table, means for adjustably securing a plate on the table in a position determined with relation to the register indices on the plate, opposed rotary cutters operably positioned adjacent the table in predetermined relation thereto, means for vertically moving the table to thereby move the plate into engagement with the a cutter whereby notches are cut in the opposed edges of the plate at points accurately locate relative to the register indices.

18. Apparatus employed in finishing printing plates having register indices marked thereon, including a vertically movableplate supporting table, means'ior adjustably securing a plate on the table in a position determined with relation to the register indices on the plate, opposed rotary cutters operably positioned adjacent the table in predetermined relation thereto, means for vertically moving the table to thereby move theplate into engagement with the cutters whereby notches are cut in the opposed edges of the plate at points accurately located relative to the register indices, and means automatically operable by the movement of the table for shielding the cutters during their cutting operation.

19. Apparatus employed in finishing printing plates having register indices marked thereon, including a-horizontally disposed plate supporting table, means for adjustably securing a plate on the table in a position determined with relation to the register indices marked on the plate,

pp d p wer-driven rotary cutters operably lo- 75 cated below the normal position of the table adjacent opposed edges thereof, manually operable. means for moving the table downwardly past the cutters thereby moving the plate into engagement with the cutters to cut register notches in opposed edges of the'plate at points accurately located with relation to the register indices on the plate, the table and plate being maintained in substantially horizontal position throughout its movement.

20. Apparatus employed in finishing printing plates having registerindices marked thereon, including a horizontally disposed plate supporting table, sighting members accurately located with respect to determined points on the table, each sighting member having a sighting index. means for adjusting a plate on the table and for securing it in a position determined by the accurate alinement of the sighting index of each sighting device with the selected register index on the plate, opposed power-driven rotary cutters operably located below the normal position or the table adjacent spaced edges thereof, manually operable means for moving the table downwardly past the cutters thereby moving the plate into engagement with the cutters to cut register notches in the opposed edges of the plate'at points accurately located with relation to the register indices on the plate, the table and plate being maintained in substantiallyhori- V zontal position throughout its movement.

21. Apparatus, employed in finishing printing plates having register indices marked thereon,

including means for forming notches in the opbendable plate holder constructed and arranged to receive a plate therein and having marginal flanges, locating fingers carried by the plate holder to engage the notches of the plate to accurately locate the plate in the holder, between the flanges, and cooperating bending rollers to bend the plate to semi-cylindrical form while in its holder so that the notches are position in the straight axial edges, of the semi-cylindrical plate.-

22. Apparatus employed in finishing printing plates having register indices former in the opposed edges thereof, including a bendable plate holder, a fixed stop member positioned in the plate holder, a yieldable-stop member operably positioned in the plate holder, locating fingers extending from the said plate holders and adapted to engage the plate notches to accurately 10- cate the plate in the holder, and bending rollers cooperating to bend the plate to semi-cylindrical form. while in its holder so that the notches are positioned in the straight axial edges of the plate, the yieldable stop members yielding to permit elongation of the plate during its bending' operation.

23. Apparatus employed in finishing semicylindrical printing plates having registerindices marked thereon, including an arcuate plate- .supporting saddle, sighting members having sighting indices and located at predetermined points with relation to the saddle, means for circumferentially moving the plate on the saddle so that the register indices marked on the plate accurately aline with the sighting indices of the sighting members, means for clamping the plate on the saddle, and means for trimming the straight axial and arcuate edges of the plate while clamped in accurately adjusted position on the saddle thereby producing a plate of accurate dimensions with its image located in definite relation to all edges of the plate.

24. Apparatus employed in finishing semicylindrical printing plates having register indices marked thereon accurately located with relation to a determined point located at or near the center of the plate, including a plate-supporting saddle, sighting members having sighting indices and located at predetermined points with relation to the saddle, means for adjusting a plate on the saddle so that the register indices marked on the plate accurately aline with the sighting indices of the sighting members, means for clamping the plateon the saddle, and means for trimming the straight axial and arcuate edges of the plate while clamped in accurately adjusted position on the saddle thereby producing a plate of accurate dimensions with its image located in definite relation to all edges of the plate and the said point.

25. Apparatus employed in finishing semicylindrical printing plates having register indices marked thereon relative to the center of the plate and register notches formed in the straight axial edges thereof at points located .with respect to the indices, including a plateplate in accurate axial relation' on the saddle,

means for circumferentially adjusting the plate on the saddle so that the register index of the sighting member accurately alines with a register index marked 'on' the plate thereby accurately positioning the plate in predetermined position on the saddle, and means for trimming the straight axial and arcuate edges of the plate while positioned on the saddle thereby producing a plate of accurate dimensions having its edges located in definite relation to its center.

26. Apparatus employed in finishing a semicylindrical printing plate having register indices marked thereon relative to the center of the plate and register notches formed in the straight axial edges thereof at points located with respect'to the indices, including a plate-supporting saddle, a sighting member having a sighting index and located at a point predetermined with relation to the saddle, manually operable means for engaging the plate notches to locate the plate in accurate axial relation on the saddle, manually operable means cooperating with the said notchengaging means for adjusting the plate circumferentially on the saddle until the register index of the sighting member accurately alines with a register index marked on the'plate to,

accurately locate the plate in predetermined position on the saddle, and means for trimming the straight axial and arcuate edges of the plate 6 I while positioned on the saddle thereby producing a plate of accurate dimensions having its edges plate in accurate axial relation on the saddle,

manually operable means cooperating with the 75 

